Sprint to launch Wi-Fi calling, but slowly

Sprint said Friday that it plans to roll out software updates that will allow users to place calls via Wi-Fi, but only only on two relatively little-used smartphones.

In the "next few" weeks, Sprint will begin rolling out the update for its Samsung Galaxy S4 Mini and S4 Mega phones, the company said in a blog post. Sprint plans to bring the Wi-Fi calling update to additional devices in 2014, the company said.

"It's not uncommon for customers to experience mobile network coverage issues within their home, apartment or office building due to materials interfering with the Sprint network," Sprint wrote. "For customers that travel outside of Sprint's coverage or experience poor coverage in their homes or office, Wi-Fi calling is a solution that addresses these issues."

The update will be sent to customers as an over-the-air update, which will require the device's ability to make calls to halt for a minute or two while the update is installed.

Essentially, Wi-Fi calling turns your cell phone call into a VOIP call. T-Mobile first launched Wi-Fi calling in 2010, and the technology is pretty pervasive throughout its network. As the name suggests, Wi-Fi calling allows users to place calls via an internal Wi-Fi network, saving cellular minutes (although T-Mobile's Wi-Fi calling originally counted against your minutes). Today, most modern plans offer unlimited minutes as part of their service, including Sprint.

Wi-Fi calling has also been said to improve the voice quality of calls, but today's modern smartphones, with their improved quality, make this a dubious proposition, too. The bottom line? If you live in a suburban or rural area, where your home happens to lie on the fringe of Sprint's service, Wi-Fi calling can be the way to eliminate a landline but still retain the confidence that you'll be able to be reached.